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Diffstat (limited to 'actionbarsherlock/src/com/actionbarsherlock/internal/widget/IcsAdapterView.java')
| -rw-r--r-- | actionbarsherlock/src/com/actionbarsherlock/internal/widget/IcsAdapterView.java | 1160 |
1 files changed, 0 insertions, 1160 deletions
diff --git a/actionbarsherlock/src/com/actionbarsherlock/internal/widget/IcsAdapterView.java b/actionbarsherlock/src/com/actionbarsherlock/internal/widget/IcsAdapterView.java deleted file mode 100644 index c786dc5c1..000000000 --- a/actionbarsherlock/src/com/actionbarsherlock/internal/widget/IcsAdapterView.java +++ /dev/null @@ -1,1160 +0,0 @@ -/* - * Copyright (C) 2006 The Android Open Source Project - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -package com.actionbarsherlock.internal.widget; - -import android.content.Context; -import android.database.DataSetObserver; -import android.os.Parcelable; -import android.os.SystemClock; -import android.util.AttributeSet; -import android.util.SparseArray; -import android.view.ContextMenu; -import android.view.SoundEffectConstants; -import android.view.View; -import android.view.ViewDebug; -import android.view.ViewGroup; -import android.view.accessibility.AccessibilityEvent; -import android.view.accessibility.AccessibilityNodeInfo; -import android.widget.Adapter; -import android.widget.AdapterView.OnItemClickListener; -import android.widget.ListView; - - -/** - * An AdapterView is a view whose children are determined by an {@link Adapter}. - * - * <p> - * See {@link ListView}, {@link GridView}, {@link Spinner} and - * {@link Gallery} for commonly used subclasses of AdapterView. - * - * <div class="special reference"> - * <h3>Developer Guides</h3> - * <p>For more information about using AdapterView, read the - * <a href="{@docRoot}guide/topics/ui/binding.html">Binding to Data with AdapterView</a> - * developer guide.</p></div> - */ -public abstract class IcsAdapterView<T extends Adapter> extends ViewGroup { - - /** - * The item view type returned by {@link Adapter#getItemViewType(int)} when - * the adapter does not want the item's view recycled. - */ - public static final int ITEM_VIEW_TYPE_IGNORE = -1; - - /** - * The item view type returned by {@link Adapter#getItemViewType(int)} when - * the item is a header or footer. - */ - public static final int ITEM_VIEW_TYPE_HEADER_OR_FOOTER = -2; - - /** - * The position of the first child displayed - */ - @ViewDebug.ExportedProperty(category = "scrolling") - int mFirstPosition = 0; - - /** - * The offset in pixels from the top of the AdapterView to the top - * of the view to select during the next layout. - */ - int mSpecificTop; - - /** - * Position from which to start looking for mSyncRowId - */ - int mSyncPosition; - - /** - * Row id to look for when data has changed - */ - long mSyncRowId = INVALID_ROW_ID; - - /** - * Height of the view when mSyncPosition and mSyncRowId where set - */ - long mSyncHeight; - - /** - * True if we need to sync to mSyncRowId - */ - boolean mNeedSync = false; - - /** - * Indicates whether to sync based on the selection or position. Possible - * values are {@link #SYNC_SELECTED_POSITION} or - * {@link #SYNC_FIRST_POSITION}. - */ - int mSyncMode; - - /** - * Our height after the last layout - */ - private int mLayoutHeight; - - /** - * Sync based on the selected child - */ - static final int SYNC_SELECTED_POSITION = 0; - - /** - * Sync based on the first child displayed - */ - static final int SYNC_FIRST_POSITION = 1; - - /** - * Maximum amount of time to spend in {@link #findSyncPosition()} - */ - static final int SYNC_MAX_DURATION_MILLIS = 100; - - /** - * Indicates that this view is currently being laid out. - */ - boolean mInLayout = false; - - /** - * The listener that receives notifications when an item is selected. - */ - OnItemSelectedListener mOnItemSelectedListener; - - /** - * The listener that receives notifications when an item is clicked. - */ - OnItemClickListener mOnItemClickListener; - - /** - * The listener that receives notifications when an item is long clicked. - */ - OnItemLongClickListener mOnItemLongClickListener; - - /** - * True if the data has changed since the last layout - */ - boolean mDataChanged; - - /** - * The position within the adapter's data set of the item to select - * during the next layout. - */ - @ViewDebug.ExportedProperty(category = "list") - int mNextSelectedPosition = INVALID_POSITION; - - /** - * The item id of the item to select during the next layout. - */ - long mNextSelectedRowId = INVALID_ROW_ID; - - /** - * The position within the adapter's data set of the currently selected item. - */ - @ViewDebug.ExportedProperty(category = "list") - int mSelectedPosition = INVALID_POSITION; - - /** - * The item id of the currently selected item. - */ - long mSelectedRowId = INVALID_ROW_ID; - - /** - * View to show if there are no items to show. - */ - private View mEmptyView; - - /** - * The number of items in the current adapter. - */ - @ViewDebug.ExportedProperty(category = "list") - int mItemCount; - - /** - * The number of items in the adapter before a data changed event occurred. - */ - int mOldItemCount; - - /** - * Represents an invalid position. All valid positions are in the range 0 to 1 less than the - * number of items in the current adapter. - */ - public static final int INVALID_POSITION = -1; - - /** - * Represents an empty or invalid row id - */ - public static final long INVALID_ROW_ID = Long.MIN_VALUE; - - /** - * The last selected position we used when notifying - */ - int mOldSelectedPosition = INVALID_POSITION; - - /** - * The id of the last selected position we used when notifying - */ - long mOldSelectedRowId = INVALID_ROW_ID; - - /** - * Indicates what focusable state is requested when calling setFocusable(). - * In addition to this, this view has other criteria for actually - * determining the focusable state (such as whether its empty or the text - * filter is shown). - * - * @see #setFocusable(boolean) - * @see #checkFocus() - */ - private boolean mDesiredFocusableState; - private boolean mDesiredFocusableInTouchModeState; - - private SelectionNotifier mSelectionNotifier; - /** - * When set to true, calls to requestLayout() will not propagate up the parent hierarchy. - * This is used to layout the children during a layout pass. - */ - boolean mBlockLayoutRequests = false; - - public IcsAdapterView(Context context) { - super(context); - } - - public IcsAdapterView(Context context, AttributeSet attrs) { - super(context, attrs); - } - - public IcsAdapterView(Context context, AttributeSet attrs, int defStyle) { - super(context, attrs, defStyle); - } - - /** - * Register a callback to be invoked when an item in this AdapterView has - * been clicked. - * - * @param listener The callback that will be invoked. - */ - public void setOnItemClickListener(OnItemClickListener listener) { - mOnItemClickListener = listener; - } - - /** - * @return The callback to be invoked with an item in this AdapterView has - * been clicked, or null id no callback has been set. - */ - public final OnItemClickListener getOnItemClickListener() { - return mOnItemClickListener; - } - - /** - * Call the OnItemClickListener, if it is defined. - * - * @param view The view within the AdapterView that was clicked. - * @param position The position of the view in the adapter. - * @param id The row id of the item that was clicked. - * @return True if there was an assigned OnItemClickListener that was - * called, false otherwise is returned. - */ - public boolean performItemClick(View view, int position, long id) { - if (mOnItemClickListener != null) { - playSoundEffect(SoundEffectConstants.CLICK); - if (view != null) { - view.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_CLICKED); - } - mOnItemClickListener.onItemClick(/*this*/null, view, position, id); - return true; - } - - return false; - } - - /** - * Interface definition for a callback to be invoked when an item in this - * view has been clicked and held. - */ - public interface OnItemLongClickListener { - /** - * Callback method to be invoked when an item in this view has been - * clicked and held. - * - * Implementers can call getItemAtPosition(position) if they need to access - * the data associated with the selected item. - * - * @param parent The AbsListView where the click happened - * @param view The view within the AbsListView that was clicked - * @param position The position of the view in the list - * @param id The row id of the item that was clicked - * - * @return true if the callback consumed the long click, false otherwise - */ - boolean onItemLongClick(IcsAdapterView<?> parent, View view, int position, long id); - } - - - /** - * Register a callback to be invoked when an item in this AdapterView has - * been clicked and held - * - * @param listener The callback that will run - */ - public void setOnItemLongClickListener(OnItemLongClickListener listener) { - if (!isLongClickable()) { - setLongClickable(true); - } - mOnItemLongClickListener = listener; - } - - /** - * @return The callback to be invoked with an item in this AdapterView has - * been clicked and held, or null id no callback as been set. - */ - public final OnItemLongClickListener getOnItemLongClickListener() { - return mOnItemLongClickListener; - } - - /** - * Interface definition for a callback to be invoked when - * an item in this view has been selected. - */ - public interface OnItemSelectedListener { - /** - * <p>Callback method to be invoked when an item in this view has been - * selected. This callback is invoked only when the newly selected - * position is different from the previously selected position or if - * there was no selected item.</p> - * - * Impelmenters can call getItemAtPosition(position) if they need to access the - * data associated with the selected item. - * - * @param parent The AdapterView where the selection happened - * @param view The view within the AdapterView that was clicked - * @param position The position of the view in the adapter - * @param id The row id of the item that is selected - */ - void onItemSelected(IcsAdapterView<?> parent, View view, int position, long id); - - /** - * Callback method to be invoked when the selection disappears from this - * view. The selection can disappear for instance when touch is activated - * or when the adapter becomes empty. - * - * @param parent The AdapterView that now contains no selected item. - */ - void onNothingSelected(IcsAdapterView<?> parent); - } - - - /** - * Register a callback to be invoked when an item in this AdapterView has - * been selected. - * - * @param listener The callback that will run - */ - public void setOnItemSelectedListener(OnItemSelectedListener listener) { - mOnItemSelectedListener = listener; - } - - public final OnItemSelectedListener getOnItemSelectedListener() { - return mOnItemSelectedListener; - } - - /** - * Extra menu information provided to the - * {@link android.view.View.OnCreateContextMenuListener#onCreateContextMenu(ContextMenu, View, ContextMenuInfo) } - * callback when a context menu is brought up for this AdapterView. - * - */ - public static class AdapterContextMenuInfo implements ContextMenu.ContextMenuInfo { - - public AdapterContextMenuInfo(View targetView, int position, long id) { - this.targetView = targetView; - this.position = position; - this.id = id; - } - - /** - * The child view for which the context menu is being displayed. This - * will be one of the children of this AdapterView. - */ - public View targetView; - - /** - * The position in the adapter for which the context menu is being - * displayed. - */ - public int position; - - /** - * The row id of the item for which the context menu is being displayed. - */ - public long id; - } - - /** - * Returns the adapter currently associated with this widget. - * - * @return The adapter used to provide this view's content. - */ - public abstract T getAdapter(); - - /** - * Sets the adapter that provides the data and the views to represent the data - * in this widget. - * - * @param adapter The adapter to use to create this view's content. - */ - public abstract void setAdapter(T adapter); - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param child Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void addView(View child) { - throw new UnsupportedOperationException("addView(View) is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param child Ignored. - * @param index Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void addView(View child, int index) { - throw new UnsupportedOperationException("addView(View, int) is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param child Ignored. - * @param params Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void addView(View child, LayoutParams params) { - throw new UnsupportedOperationException("addView(View, LayoutParams) " - + "is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param child Ignored. - * @param index Ignored. - * @param params Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void addView(View child, int index, LayoutParams params) { - throw new UnsupportedOperationException("addView(View, int, LayoutParams) " - + "is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param child Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void removeView(View child) { - throw new UnsupportedOperationException("removeView(View) is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @param index Ignored. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void removeViewAt(int index) { - throw new UnsupportedOperationException("removeViewAt(int) is not supported in AdapterView"); - } - - /** - * This method is not supported and throws an UnsupportedOperationException when called. - * - * @throws UnsupportedOperationException Every time this method is invoked. - */ - @Override - public void removeAllViews() { - throw new UnsupportedOperationException("removeAllViews() is not supported in AdapterView"); - } - - @Override - protected void onLayout(boolean changed, int left, int top, int right, int bottom) { - mLayoutHeight = getHeight(); - } - - /** - * Return the position of the currently selected item within the adapter's data set - * - * @return int Position (starting at 0), or {@link #INVALID_POSITION} if there is nothing selected. - */ - @ViewDebug.CapturedViewProperty - public int getSelectedItemPosition() { - return mNextSelectedPosition; - } - - /** - * @return The id corresponding to the currently selected item, or {@link #INVALID_ROW_ID} - * if nothing is selected. - */ - @ViewDebug.CapturedViewProperty - public long getSelectedItemId() { - return mNextSelectedRowId; - } - - /** - * @return The view corresponding to the currently selected item, or null - * if nothing is selected - */ - public abstract View getSelectedView(); - - /** - * @return The data corresponding to the currently selected item, or - * null if there is nothing selected. - */ - public Object getSelectedItem() { - T adapter = getAdapter(); - int selection = getSelectedItemPosition(); - if (adapter != null && adapter.getCount() > 0 && selection >= 0) { - return adapter.getItem(selection); - } else { - return null; - } - } - - /** - * @return The number of items owned by the Adapter associated with this - * AdapterView. (This is the number of data items, which may be - * larger than the number of visible views.) - */ - @ViewDebug.CapturedViewProperty - public int getCount() { - return mItemCount; - } - - /** - * Get the position within the adapter's data set for the view, where view is a an adapter item - * or a descendant of an adapter item. - * - * @param view an adapter item, or a descendant of an adapter item. This must be visible in this - * AdapterView at the time of the call. - * @return the position within the adapter's data set of the view, or {@link #INVALID_POSITION} - * if the view does not correspond to a list item (or it is not currently visible). - */ - public int getPositionForView(View view) { - View listItem = view; - try { - View v; - while (!(v = (View) listItem.getParent()).equals(this)) { - listItem = v; - } - } catch (ClassCastException e) { - // We made it up to the window without find this list view - return INVALID_POSITION; - } - - // Search the children for the list item - final int childCount = getChildCount(); - for (int i = 0; i < childCount; i++) { - if (getChildAt(i).equals(listItem)) { - return mFirstPosition + i; - } - } - - // Child not found! - return INVALID_POSITION; - } - - /** - * Returns the position within the adapter's data set for the first item - * displayed on screen. - * - * @return The position within the adapter's data set - */ - public int getFirstVisiblePosition() { - return mFirstPosition; - } - - /** - * Returns the position within the adapter's data set for the last item - * displayed on screen. - * - * @return The position within the adapter's data set - */ - public int getLastVisiblePosition() { - return mFirstPosition + getChildCount() - 1; - } - - /** - * Sets the currently selected item. To support accessibility subclasses that - * override this method must invoke the overriden super method first. - * - * @param position Index (starting at 0) of the data item to be selected. - */ - public abstract void setSelection(int position); - - /** - * Sets the view to show if the adapter is empty - */ - public void setEmptyView(View emptyView) { - mEmptyView = emptyView; - - final T adapter = getAdapter(); - final boolean empty = ((adapter == null) || adapter.isEmpty()); - updateEmptyStatus(empty); - } - - /** - * When the current adapter is empty, the AdapterView can display a special view - * call the empty view. The empty view is used to provide feedback to the user - * that no data is available in this AdapterView. - * - * @return The view to show if the adapter is empty. - */ - public View getEmptyView() { - return mEmptyView; - } - - /** - * Indicates whether this view is in filter mode. Filter mode can for instance - * be enabled by a user when typing on the keyboard. - * - * @return True if the view is in filter mode, false otherwise. - */ - boolean isInFilterMode() { - return false; - } - - @Override - public void setFocusable(boolean focusable) { - final T adapter = getAdapter(); - final boolean empty = adapter == null || adapter.getCount() == 0; - - mDesiredFocusableState = focusable; - if (!focusable) { - mDesiredFocusableInTouchModeState = false; - } - - super.setFocusable(focusable && (!empty || isInFilterMode())); - } - - @Override - public void setFocusableInTouchMode(boolean focusable) { - final T adapter = getAdapter(); - final boolean empty = adapter == null || adapter.getCount() == 0; - - mDesiredFocusableInTouchModeState = focusable; - if (focusable) { - mDesiredFocusableState = true; - } - - super.setFocusableInTouchMode(focusable && (!empty || isInFilterMode())); - } - - void checkFocus() { - final T adapter = getAdapter(); - final boolean empty = adapter == null || adapter.getCount() == 0; - final boolean focusable = !empty || isInFilterMode(); - // The order in which we set focusable in touch mode/focusable may matter - // for the client, see View.setFocusableInTouchMode() comments for more - // details - super.setFocusableInTouchMode(focusable && mDesiredFocusableInTouchModeState); - super.setFocusable(focusable && mDesiredFocusableState); - if (mEmptyView != null) { - updateEmptyStatus((adapter == null) || adapter.isEmpty()); - } - } - - /** - * Update the status of the list based on the empty parameter. If empty is true and - * we have an empty view, display it. In all the other cases, make sure that the listview - * is VISIBLE and that the empty view is GONE (if it's not null). - */ - private void updateEmptyStatus(boolean empty) { - if (isInFilterMode()) { - empty = false; - } - - if (empty) { - if (mEmptyView != null) { - mEmptyView.setVisibility(View.VISIBLE); - setVisibility(View.GONE); - } else { - // If the caller just removed our empty view, make sure the list view is visible - setVisibility(View.VISIBLE); - } - - // We are now GONE, so pending layouts will not be dispatched. - // Force one here to make sure that the state of the list matches - // the state of the adapter. - if (mDataChanged) { - this.onLayout(false, getLeft(), getTop(), getRight(), getBottom()); - } - } else { - if (mEmptyView != null) mEmptyView.setVisibility(View.GONE); - setVisibility(View.VISIBLE); - } - } - - /** - * Gets the data associated with the specified position in the list. - * - * @param position Which data to get - * @return The data associated with the specified position in the list - */ - public Object getItemAtPosition(int position) { - T adapter = getAdapter(); - return (adapter == null || position < 0) ? null : adapter.getItem(position); - } - - public long getItemIdAtPosition(int position) { - T adapter = getAdapter(); - return (adapter == null || position < 0) ? INVALID_ROW_ID : adapter.getItemId(position); - } - - @Override - public void setOnClickListener(OnClickListener l) { - throw new RuntimeException("Don't call setOnClickListener for an AdapterView. " - + "You probably want setOnItemClickListener instead"); - } - - /** - * Override to prevent freezing of any views created by the adapter. - */ - @Override - protected void dispatchSaveInstanceState(SparseArray<Parcelable> container) { - dispatchFreezeSelfOnly(container); - } - - /** - * Override to prevent thawing of any views created by the adapter. - */ - @Override - protected void dispatchRestoreInstanceState(SparseArray<Parcelable> container) { - dispatchThawSelfOnly(container); - } - - class AdapterDataSetObserver extends DataSetObserver { - - private Parcelable mInstanceState = null; - - @Override - public void onChanged() { - mDataChanged = true; - mOldItemCount = mItemCount; - mItemCount = getAdapter().getCount(); - - // Detect the case where a cursor that was previously invalidated has - // been repopulated with new data. - if (IcsAdapterView.this.getAdapter().hasStableIds() && mInstanceState != null - && mOldItemCount == 0 && mItemCount > 0) { - IcsAdapterView.this.onRestoreInstanceState(mInstanceState); - mInstanceState = null; - } else { - rememberSyncState(); - } - checkFocus(); - requestLayout(); - } - - @Override - public void onInvalidated() { - mDataChanged = true; - - if (IcsAdapterView.this.getAdapter().hasStableIds()) { - // Remember the current state for the case where our hosting activity is being - // stopped and later restarted - mInstanceState = IcsAdapterView.this.onSaveInstanceState(); - } - - // Data is invalid so we should reset our state - mOldItemCount = mItemCount; - mItemCount = 0; - mSelectedPosition = INVALID_POSITION; - mSelectedRowId = INVALID_ROW_ID; - mNextSelectedPosition = INVALID_POSITION; - mNextSelectedRowId = INVALID_ROW_ID; - mNeedSync = false; - - checkFocus(); - requestLayout(); - } - - public void clearSavedState() { - mInstanceState = null; - } - } - - @Override - protected void onDetachedFromWindow() { - super.onDetachedFromWindow(); - removeCallbacks(mSelectionNotifier); - } - - private class SelectionNotifier implements Runnable { - public void run() { - if (mDataChanged) { - // Data has changed between when this SelectionNotifier - // was posted and now. We need to wait until the AdapterView - // has been synched to the new data. - if (getAdapter() != null) { - post(this); - } - } else { - fireOnSelected(); - } - } - } - - void selectionChanged() { - if (mOnItemSelectedListener != null) { - if (mInLayout || mBlockLayoutRequests) { - // If we are in a layout traversal, defer notification - // by posting. This ensures that the view tree is - // in a consistent state and is able to accomodate - // new layout or invalidate requests. - if (mSelectionNotifier == null) { - mSelectionNotifier = new SelectionNotifier(); - } - post(mSelectionNotifier); - } else { - fireOnSelected(); - } - } - - // we fire selection events here not in View - if (mSelectedPosition != ListView.INVALID_POSITION && isShown() && !isInTouchMode()) { - sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_SELECTED); - } - } - - private void fireOnSelected() { - if (mOnItemSelectedListener == null) - return; - - int selection = this.getSelectedItemPosition(); - if (selection >= 0) { - View v = getSelectedView(); - mOnItemSelectedListener.onItemSelected(this, v, selection, - getAdapter().getItemId(selection)); - } else { - mOnItemSelectedListener.onNothingSelected(this); - } - } - - @Override - public boolean dispatchPopulateAccessibilityEvent(AccessibilityEvent event) { - View selectedView = getSelectedView(); - if (selectedView != null && selectedView.getVisibility() == VISIBLE - && selectedView.dispatchPopulateAccessibilityEvent(event)) { - return true; - } - return false; - } - - @Override - public boolean onRequestSendAccessibilityEvent(View child, AccessibilityEvent event) { - if (super.onRequestSendAccessibilityEvent(child, event)) { - // Add a record for ourselves as well. - AccessibilityEvent record = AccessibilityEvent.obtain(); - onInitializeAccessibilityEvent(record); - // Populate with the text of the requesting child. - child.dispatchPopulateAccessibilityEvent(record); - event.appendRecord(record); - return true; - } - return false; - } - - @Override - public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) { - super.onInitializeAccessibilityNodeInfo(info); - info.setScrollable(isScrollableForAccessibility()); - View selectedView = getSelectedView(); - if (selectedView != null) { - info.setEnabled(selectedView.isEnabled()); - } - } - - @Override - public void onInitializeAccessibilityEvent(AccessibilityEvent event) { - super.onInitializeAccessibilityEvent(event); - event.setScrollable(isScrollableForAccessibility()); - View selectedView = getSelectedView(); - if (selectedView != null) { - event.setEnabled(selectedView.isEnabled()); - } - event.setCurrentItemIndex(getSelectedItemPosition()); - event.setFromIndex(getFirstVisiblePosition()); - event.setToIndex(getLastVisiblePosition()); - event.setItemCount(getCount()); - } - - private boolean isScrollableForAccessibility() { - T adapter = getAdapter(); - if (adapter != null) { - final int itemCount = adapter.getCount(); - return itemCount > 0 - && (getFirstVisiblePosition() > 0 || getLastVisiblePosition() < itemCount - 1); - } - return false; - } - - @Override - protected boolean canAnimate() { - return super.canAnimate() && mItemCount > 0; - } - - void handleDataChanged() { - final int count = mItemCount; - boolean found = false; - - if (count > 0) { - - int newPos; - - // Find the row we are supposed to sync to - if (mNeedSync) { - // Update this first, since setNextSelectedPositionInt inspects - // it - mNeedSync = false; - - // See if we can find a position in the new data with the same - // id as the old selection - newPos = findSyncPosition(); - if (newPos >= 0) { - // Verify that new selection is selectable - int selectablePos = lookForSelectablePosition(newPos, true); - if (selectablePos == newPos) { - // Same row id is selected - setNextSelectedPositionInt(newPos); - found = true; - } - } - } - if (!found) { - // Try to use the same position if we can't find matching data - newPos = getSelectedItemPosition(); - - // Pin position to the available range - if (newPos >= count) { - newPos = count - 1; - } - if (newPos < 0) { - newPos = 0; - } - - // Make sure we select something selectable -- first look down - int selectablePos = lookForSelectablePosition(newPos, true); - if (selectablePos < 0) { - // Looking down didn't work -- try looking up - selectablePos = lookForSelectablePosition(newPos, false); - } - if (selectablePos >= 0) { - setNextSelectedPositionInt(selectablePos); - checkSelectionChanged(); - found = true; - } - } - } - if (!found) { - // Nothing is selected - mSelectedPosition = INVALID_POSITION; - mSelectedRowId = INVALID_ROW_ID; - mNextSelectedPosition = INVALID_POSITION; - mNextSelectedRowId = INVALID_ROW_ID; - mNeedSync = false; - checkSelectionChanged(); - } - } - - void checkSelectionChanged() { - if ((mSelectedPosition != mOldSelectedPosition) || (mSelectedRowId != mOldSelectedRowId)) { - selectionChanged(); - mOldSelectedPosition = mSelectedPosition; - mOldSelectedRowId = mSelectedRowId; - } - } - - /** - * Searches the adapter for a position matching mSyncRowId. The search starts at mSyncPosition - * and then alternates between moving up and moving down until 1) we find the right position, or - * 2) we run out of time, or 3) we have looked at every position - * - * @return Position of the row that matches mSyncRowId, or {@link #INVALID_POSITION} if it can't - * be found - */ - int findSyncPosition() { - int count = mItemCount; - - if (count == 0) { - return INVALID_POSITION; - } - - long idToMatch = mSyncRowId; - int seed = mSyncPosition; - - // If there isn't a selection don't hunt for it - if (idToMatch == INVALID_ROW_ID) { - return INVALID_POSITION; - } - - // Pin seed to reasonable values - seed = Math.max(0, seed); - seed = Math.min(count - 1, seed); - - long endTime = SystemClock.uptimeMillis() + SYNC_MAX_DURATION_MILLIS; - - long rowId; - - // first position scanned so far - int first = seed; - - // last position scanned so far - int last = seed; - - // True if we should move down on the next iteration - boolean next = false; - - // True when we have looked at the first item in the data - boolean hitFirst; - - // True when we have looked at the last item in the data - boolean hitLast; - - // Get the item ID locally (instead of getItemIdAtPosition), so - // we need the adapter - T adapter = getAdapter(); - if (adapter == null) { - return INVALID_POSITION; - } - - while (SystemClock.uptimeMillis() <= endTime) { - rowId = adapter.getItemId(seed); - if (rowId == idToMatch) { - // Found it! - return seed; - } - - hitLast = last == count - 1; - hitFirst = first == 0; - - if (hitLast && hitFirst) { - // Looked at everything - break; - } - - if (hitFirst || (next && !hitLast)) { - // Either we hit the top, or we are trying to move down - last++; - seed = last; - // Try going up next time - next = false; - } else if (hitLast || (!next && !hitFirst)) { - // Either we hit the bottom, or we are trying to move up - first--; - seed = first; - // Try going down next time - next = true; - } - - } - - return INVALID_POSITION; - } - - /** - * Find a position that can be selected (i.e., is not a separator). - * - * @param position The starting position to look at. - * @param lookDown Whether to look down for other positions. - * @return The next selectable position starting at position and then searching either up or - * down. Returns {@link #INVALID_POSITION} if nothing can be found. - */ - int lookForSelectablePosition(int position, boolean lookDown) { - return position; - } - - /** - * Utility to keep mSelectedPosition and mSelectedRowId in sync - * @param position Our current position - */ - void setSelectedPositionInt(int position) { - mSelectedPosition = position; - mSelectedRowId = getItemIdAtPosition(position); - } - - /** - * Utility to keep mNextSelectedPosition and mNextSelectedRowId in sync - * @param position Intended value for mSelectedPosition the next time we go - * through layout - */ - void setNextSelectedPositionInt(int position) { - mNextSelectedPosition = position; - mNextSelectedRowId = getItemIdAtPosition(position); - // If we are trying to sync to the selection, update that too - if (mNeedSync && mSyncMode == SYNC_SELECTED_POSITION && position >= 0) { - mSyncPosition = position; - mSyncRowId = mNextSelectedRowId; - } - } - - /** - * Remember enough information to restore the screen state when the data has - * changed. - * - */ - void rememberSyncState() { - if (getChildCount() > 0) { - mNeedSync = true; - mSyncHeight = mLayoutHeight; - if (mSelectedPosition >= 0) { - // Sync the selection state - View v = getChildAt(mSelectedPosition - mFirstPosition); - mSyncRowId = mNextSelectedRowId; - mSyncPosition = mNextSelectedPosition; - if (v != null) { - mSpecificTop = v.getTop(); - } - mSyncMode = SYNC_SELECTED_POSITION; - } else { - // Sync the based on the offset of the first view - View v = getChildAt(0); - T adapter = getAdapter(); - if (mFirstPosition >= 0 && mFirstPosition < adapter.getCount()) { - mSyncRowId = adapter.getItemId(mFirstPosition); - } else { - mSyncRowId = NO_ID; - } - mSyncPosition = mFirstPosition; - if (v != null) { - mSpecificTop = v.getTop(); - } - mSyncMode = SYNC_FIRST_POSITION; - } - } - } -} |